Design Of Isolating Switch For Anti-Misoperation Of Electric Railway

The announcement of the mid-long term railway network plan indicates that China’s electric railway is getting into a new golden period of development.Over contact line,infrastructure of electrified railway,is constructed in open air without standby and the working environment is bad,so it needs regular or irregular maintenance.Over contact line maintenance is high altitude and high risk operations.Existing major security measures are grounding wires and interlocking switch equipment.Once traction substation fault electric accident occurs and substation operator switches on the isolating switch on the line in overhaul,it will directly threaten the life safety of maintenance personnel.In order to make up for the shortcomings of the existing electric anti miscarriage measures,we have designed a new type of anti miscarriage scheme composed of special isolating switch which could rotate bidirectional 90 degree.The new scheme determines whether the switching equipments on the line meet closing conditions through the real-time detection of the over contact line maintenance status.Due to the closing lock signal of switching equipments is not affected by the influence of subjective behavior of power supply dispatcher or substation attendant,it can avoid the miscarriage of the electricity accident caused by human factors.Based on working principles of the new anti miscarriage power scheme,we have designed a special isolating switch for electric anti miscarriage and the corresponding electric operating mechanism.Then we have described the structure and working principles of two devices in detail.Through improving the body structure of the special isolating switch and changing the insulating pillar arrangement from triangle to linear shape,we have improved the precision of rotation of isolating switch.Based on continuous contact model,we have modeled hinge clearance in four bar linkage transmission mechanism of isolating switch and calculated the transmission error of mechanism with single clearance,double clearances or four clearances separately by using MATLAB programming.It concludes that the transmission error value increases with the increase of the number and numerical value of hinge clearance.Then we design a bevel gear transmission mechanism innovatively and select the material and precision of bevel gear,calculate other parameters according to the working environment of isolating switch.We also analyze the transmission accuracy of bevel gear mechanism using Monte Carlo method and conclude that the bevel gear mechanism can improve the transmission accuracy by more than 99%.We have produced anti miscarriage electric special isolation switch prototype.The product has been put into application at part of traction substation of Shenhua quasi pool Railway and works well.